Block bottom dispenser



Feb. 18, 1969 P. E. WITMER' .BLOCK BOTTOM DISPENSER Sheet of 3 Filed Sept.A 12. 196'/ Feb. 18, 1969 p E, wrrMER 3,428,192

BLOCK BOTTOM DISPENSER Filed Sept. l2, 1967 Sheet 2 of 5 j; mmm @Um mmm I8 mmm @UU mmm mmm mmm mmm se -A'Lv m0. 4 'La 411m To /A/r/EA/ro/Z, 'n 'LB @40A /t//MEZ BLOCK BOTTOM DISPENSER Arrow/Ys United States Patent O 6 Claims ABSTRACT F THE DISCLOSURE Apparatus triggered by the movement of a cart beneath a stack of building blocks supported by the apparatus commences an automatic cycle of operation in which the apparatus deposits a layer of blocks from the bottom of the stack onto the cart, then raises the remainder of the stack clear of the deposited layer to permit removal of the cart and its replacement by another cart for a new cycle.

Background of the invention In transporting building blocks such as conventional cinder or concrete blocks of various sizes and types from the source of manufacture or other centralized location to diversified points of use, it has become customary to stack the blocks on a conventional pallet. The pallet will normally have means for supporting itself in spaced relation above the Vground or loading platform whereby the pallet and blocks may readily be picked up, loaded, and unloaded from a truck, railway car, etc. and restacked at the point of use. The pallets thus employed are frequently damaged, destroyed, or lost so that the rate of recovery thereof by the block maker or supplier is quite low. Due to the substantial expense of the pallets, such loss represents a considerable outlay.

In lieu of the pallets, it has been known to arrange a layer of hollow blocks with their openings similarly oriented to serve for reception of the lift arms of the fork-lift truck, and to so bind together this layer of blocks that it may support a number of other layers of the same or different types of blocks thereon, permitting handling of the entire stack of blocks by thus utilizing its bottom layer as a support in lieu of the pallet.

Such substitution of properly-arranged hollow blocks in place of pallets has, however, required an outlay of manual labor for properly positioning each layer of blocks to form the bottom layer of the stack to be subsequently formed, it being thus necessary that each layer either be formed at the location of its intended use, or that successive layers be formed at a single location for transport to their points of use. In the latter event, moreover, it has been required that, each time an empty transport car or cart is available at the layer-forming point, there must be labor available at its time of arrival to proceed with the formation of the layer.

The present invention has been conceived primarily for the purpose of providing an apparatus for maintaining a suitably-elevated supply or stack of blocks arranged in properly-oriented layers of blocks so that, when transport carts or conveyers are successively moved to locations therebeneath, there will automatically be deposited on each cart in succession a single layer of properly-oriented blocks from the bottom of the stack, the remainder of the stack being raised clear of the layer thus deposited and maintained in readiness to deposit a further layer on a fresh cart, while also providing clearance for removal of the cart with the layer just deposited. By rendering the apparatus operative through successive cycles, each of which is triggered by the arrival of a cart in operative position for reception of a layer of blocks, the invention requires only such manual labor as may be necessary to 3,428,192 Patented Feb. 18, 1969 ice maintain an adequate stack of blocks in position for delivery to the successive carts, whereby each layer deposited on a cart may thereby be transported to a subsequent location to have formed thereon a stack of blocks of any desired type and orientation, the bottom layer in such event providing means in lieu of a pallet for enabling handling of the stack of such blocks by a conventional fork-lift truck with suitably-disposed lift arms.

Summary of the invention In order to achieve the foregoing, the apparatus of the present invention includes a grapple which is suspended over a suitable horizontally intermittently-moving conveyer means. The grapple includes horizontally-opposed clamp members, together with means for alternately raising and lowering the grapple and for engaging and disengaging the clamp members with a given layer of blocks of the stack. Normally, the clamp means engage and compress horizontally between them the lower or bottom layer of the stack, thereby rendering same substantially rigid so as to afford a supporting base layer for the additional layers of blocks of the stack which will rest thereon.

With the grapple supporting the stack of blocks in raised position, intermittently moving conveyer means, when brought to rest thereto beneath the stack, automatically triggers an automatic cycle of operation of the grapple during which the latter lowers its stack of blocks onto the conveyer, releases the bottom layer thereof, and then commences its upward return toward its original position. Midway of such return movement, clamp members of the grapple are engaged with the next layer of blocks above the bottom so that, during the completion of the return movement, the stack minus the layer deposited upon the cart is raised free of said deposited layer whereby the conveyer is free to move the deposited layer in horizontal direction for subsequent use. The grapple and its supported stack is then retained in its position of rest pending the bringing of another conveyer portion or element to rest therebeneath. While the apparatus of the invention is primarily intended for dispensing layers of blocks for use in providing supporting layers on which stacks of blocks may subsequently be formed and transported, it is by no means limited to this specific use and is obviously adapted for any use involving deposit of successive layers of blocks from the bottom of a stack thereof.

Description of the drawings In the accompanying drawings:

FIGURE 1 is a front perspective View of a block bottom layer dispenser in accordance with the preferred embodiment of the invention.

FIGURES 2a and 2b are views of one of the clamp mechanisms showing it respectively in its inoperative and operative positions.

FIGURE 3 is a front elevation of the dispenser.

FIGURE 4 is a rear elevation.

FIGURE 5 is a fragmentary end elevation as seen from the plane 5--5 in FIGURE 1.

FIGURE 6` is an end elevation as seen from the line 6 6 at the right hand side of FIGURE l.

Descriptionl of the preferred embodiment Referring now in detail to the preferred embodiment of the invention illustrated in the accompanying drawings, the particular horizontal conveying means employed with the invention here illustrated has a pair of parallel rails 10-10 which may extend in an endless loop, together with one or more wheeled carts 12 which are guided in usual manner for movement around the rails. Each of such carts is self-powered by means of an electric driving motor 14 connected in driving relation to the wheels through a gear reduction transmission unit 16. The current for the motor may suitably be supplied through a circuit which includes one of the rails as a lead from which the energy is taken olf and delivered to the motor, as for instance through a suitable brush, and grounded in the same manner through the other rail. interposed in such circuit is a switch M1 hereinafter referred to in detail for controlling the movement and positioning of the cart.

The grapple means or mechanism of the invention comprises a rigid supporting structure or frame F which straddles the rails 10-10 and which includes the upright members 18 interconnected in suitable manner to form a complete rigid structure. Supported by such frame is a bottomless hopper 20 having longitudinally-opposed vertical end plates 22-22, the lower edges of which are located substantially above the rails 10`10 and the path of movement of the conveyor. The hopper may also include a rear wall 24 which is disposed wholly on one side of the track and thus clear of the movement of the conveyor carts, although the front of the hopper is preferably left fully open and unobstructed to facilitate the manual disposition and stacking of the blocks, the purpose of the hopper being to accurately locate the blocks with respect to the grapple and its associated clamp members as hereinafter described.

The grapple comprises an elevator here shown in the form of a generally-rectangular horizontal frame 26 consisting of the relatively longitudinally-spaced transverselydisposed rock shafts 28 journalled at opposite longitudinal ends of the frame and the relatively-parallel horizontal front and rear frame members 30 through which the rock shafts are rotatably journalled. In the preferred embodiment, the grapple frame 26 is located entirely outside of the hopper and its supporting frame members 18. The grapple frame 26 is suspended and supported for vertical movement below the hopper 20. Por this purpose, there are shown, at opposite ends of the hopper, a pair of horizontal crank shafts 32 which are rotatably journalled on the frame F above the grapple frame 26. The cranks 34 afxed to the forward end portions of the respective shafts 32 have their free ends connected by the connecting rods 36 to the respective forward ends of the rock shafts 28. Similarly, at the rear end of each shaft 32, there is provided a crank which is defined by a crank pin 38 eccentrically located on a sprocket wheel 40, which in turn is keyed or otherwise iixed on the crank shaft. The rear connecting rods `42 connect the rear ends of the respective rock shafts to the crank pins 38. It will be seen that the cranks of each shaft are of equal effective radius and extend in a common radial plane from their respective shafts.

If desired, a threaded coupling 43 is interposed in each connecting rod 36 and 42 for adjusting the length thereof, to control the range of movement of the grapple frame 26.

Moreover, the shafts 32 are interconnected for equal but opposite angular movement by means here exemplitied by the sprocket drive chain 44, the lower run of which extends over the top of the one sprocket wheel and thence beneath the bottom of the other sprocket wheel so as to achieve the opposite rotation. Driving forces are imparted to the chain 44 through a drive sprocket 46 on the output shaft of a gear reduction unit 48 through means of the drive sprocket keyed on such output shaft. The sprocket chain 44 also is entrained about an idler sprocket 50 as shown in the drawings.

Driving force is transmitted to the reduction gearing transmission unit 48 from a conventional electric motor 52 which is affixed to and supported on a bracket S4 at one end of the hopper. The reduction unit 4 8 is similarly supported by a bracket 56 having a vertical web 58 which affords a support for the idler sprocket 50 above mentioned.

'It will be seen that the driving torque from the motor is transmitted through the flexible drive 60 to the input shaft of the reduction gearing unit.

The electric circuit for the motor 52 may be manually controlled by conventional switch means (not shown) and it also preferably includes suitable switch means, hereinafter described, by which the motor is automatically controlled in order to cause the grapple to be raised and lowered in proper sequence during each cycle of operation.

Supported at opposite ends of the grapple frame 26 for opposite longitudinal movement into and from clamping engagement with the blocks are a pair of longitudinally-opposed clamp members 62 adapted for engagement with the blocks beneath the lower edges of the end plates 22 of the hopper 20. In order to facilitate the action of the end plates 22 in properly centering the stack of blocks between the clamp members 62, it is desirable to provide, adjacent the lower edges of the end plates, the horizontally-extending guides 64 having inwardly-converging surfaces arranged to thrust blocks inwardly toward the center of the hopper and somewhat clear of the upper portions of the side walls, and in general to so position the blocks that the blocks at the ends of the bottom layer will be normally disengaged from the clamp plates or members 62 when the latter are retracted.

Clamp structure In the preferred exempliiication, one of the clamp members 62 comprises a at metal plate which is supported by relatively-spaced crank arms 66 extending from the horizontal rock shaft 28 at one end of the elevator or grapple frame 26. The arrangement is such that rocking of the shaft causes the clamp plate to approach or recede from the blocks to be gripped by it. Preferably, the clamp plate 62 is pivotally connected, as shown, to the free ends of its supporting crank arms 66 for limited swinging movement about a horizontal axis parallel to the rock shaft 28 and located medially of the height of the clamp plate so that the latter will automatically tend to assume a position in flush engagement with the generallyvertical faces of the opposed blocks which it engages. To decrease the likelihood of catching the upper edges of the clamp beneath any overhanging or projecting blocks B during upward movement of the grapple frame 26 with the clamps or clamp members disengaged, the clamp plate 62 is angularly biased to resiliently urge its upper edge portion outwardly away from the blocks and is free of any ledges or horizontal projections which might extend beneath the blocks. For this purpose, there is provided a retraction spring 68 tensioned between the clamp plate above its pivotal axis and a spring attachment arm 70 affixed t0 the grapple frame.

In order to maintain the clamp member in generally upright position when retracted from the blocks, the degree of its pivotal motion is preferably restricted by one or more lost-motion linkages in each of which the rigid link 76 is pivotally connected to one end of its clamp plate 62 at a location eccentric to its pivotal axis, and is pivotally connected by a pin and slot connection 78l to a bracket afxed on the arm whereby to afford a limited degree of lost motion.

The clamp member 62 above described is preferably of sufficient length to extend across the entire stack of blocks so as to simultaneously engage the opposed vertical faces of all of the blocks of a given layer.

To compensate for slight differences in dimensions of blocks such as might result in variation in lengths of different longitudinal rows between the clamp members, it has been found desirable to subdivide the other clamp member into a plurality of separate clamp segments 62', each proportioned and positioned for engagement with but a single block. As with the clamp member 62 earlier described, the individual clamp segments 62' respectively are pivotally supported from their associated rock shaft at the free ends of rigid arms 66 atiixed to the rock shaft 28 for operative engaging and retraction movement about the horizontal axis of the rock shaft. As described in connection with the clamp member 62, the upper edges of each of the individual clamp segments 62 preferably are resiliently urged away from the `blocks B by means of retraction springs 68, such swinging movement `being limited by lost motion linkages, such as earlier described, in which the attachment arms 70 for the respective springs 68 and lost-motion linkages 76 are supported by a cross bar 72 aixed to the frame 26.

Throughout the range of operative movement of the clamp members 62, 62', their supporting crank arms 66 extend upwardly and inwardly from their respective rock shafts 28 so that the opposed clamp members 62, 62 will be caused to approach each other for gripping engagement with blocks B interposed between them incident to downward swinging of the respective rock shafts in opposite directions to bring the crank arms downwardly toward horizontal positions.

Because of this, Once the clamp members 62, 62' have swung into substantial frictional engagement with the blocks, the lifting force applied to the grapple frame 26 in opposition to the weight of the blocks B Will exert on the clamp members a toggle action tending to increase their clamping or gripping action.

For actuating the clamp members to engage or disengage them from their blocks, there is provided a suitable mechanism carried by the grapple frame.

In the form exemplified in the accompanying drawings, such actuating means or mechanism comprises a doubleacting pneumatic piston and cylinder unit 80 in which the supply and exhaust of air for actuating the unit are controlled by a conventional solenoid actuated reversing valve 82 capable of selectively extending and retracting the unit. It will be seen that the cylinder of the pneumatic unit is connected to and suspended from a rigid superstructure 84 which, in turn, is aixed to the grapple frame by way of the rear frame rail or member 30.

The downwardly-projecting end of the piston rod of the unit is connected to the knee 86 of a toggle linkage in which the toggle links 88, 88 respectively diverge downwardly from the knee and have their remote ends pivotally connected at 90, 90 respectively to quadrant plates which are pivotally supported at 94, 94 from brackets 96 re' spectively aixed to the grapple frame 26.

The toggle knee `86 preferably comprises a pivot pin which 4projects somewhat from the interconnected ends of the toggle links 88 and has rollers 98 journalled on its projecting ends. These rollers respectively are guided for movement in a vertical plane between pairs of relativelyspaced vertical rails 100 constituting part of the superstructure. Since the linkage, as above described, is arranged symmetrically to the vertical plane in which the toggle knee 86 moves, its movement will impart equal but opposite swinging movement to the quadrant plates 92. Each quadrant plate 92, in turn, is connected by a rigid link 102 to an actuating lever or crank arm affixed to its adjacent rock shaft 28 to thus translate the extension and retraction movement of the pneumatic unit into equal and opposite clamp actuating and retracting movements.

Thus, downward movement of the toggle knee 86 incident to extension of the pneumatic unit 80 causes the toggle links 88, quadrant plates 92, and connecting rods 102 to transmit a thrusting force to the actuating arms 104 of the rock shafts 28 in directions to retract the respective clamp members 62, 62 from the blocks B, whereas retraction of the double acting pneumatic unit 80 transmits tension through the aforesaid linkage to move the clamp members toward each other into operative gripping engagement with any blocks interposed bet-Ween them.

Automatic control of the clamp releasing and gripping action, in coordination with the vertical movement of the grapple, is achieved as follows:

In the preferred embodiment, the controls for the vertical movement of the grapple or elevator frame comprise a series of switches in circuit with its driving motor. In addition to the cart actuated switch M1 earlier described, these comprise a series of switches M2, M3 and M4 (see FIGURE 6). Of these, the switch M2 is mounted on the outer face of one end wall of the hopper above the crank shaft at that end with its actuating arm disposed for control by means of a cam 116 axed to the crank shaft 32 and arranged to arrest the downward movement of the grapple frame 26 when the latter is in substantially its lowered position to deposit .a layer of blocks on the cart 12.

The switch M5 has its control arm 108 resiliently `biased toward a circuit opening position. This switch is mounted at the rear of the apparatus, as for instance on the superstructure 84, with its control arm 108 positioned in the path of movement of one of the toggle links 88 to close a circuit to the grapple motor, whereby the latter will be energized incident to opening or spreading of the clamp members to release the lowered stack of blocks onto the flat #bed of the cart.

The switch M4 has its actuating arm normally resiliently biased to a closed position. This switch, in the present embodiment, is mounted on the outer face of one end wall of the hopper above the crank shaft at that end, with its .actuating arm disposed for control by means of la cam 112 afxed to the crank shaft 32 and arranged to open said switch when the grapple is raised to its intended position of rest at the end of each cycle of operation. The same switch M4 also preferably controls an energizing circuit to the cart motor 14 to energize the cart motor simultaneously with de-energizing of the grapple motor 52.

For automatically controlling the clamp members 62, 62 to actuate them in properly-coordinated relation with the vertical movement of the grapple frame 26, there are provided, on the hopper end wall above the crank shaft, a pair oi switches M2 and M3 both in circuit with the solenoid of reversing valve 82 and arranged respectively for actuation `by cam members 116 and 114 atiixed to the crank shaft. The rst of these switches M2 is actuated by its associated cam member 116 incident to lowering of the grapple frame 26 to arrest the downward movement of the grapple, as earlier described and in addition to actuate valve 82 to release the blocks B and thus place its stack of blocks B on the supporting cart 12, while the seocnd such switch M3 is engaged by its associated cam 114 and energized to cause generally-horizontal movement of the clamp members 62, 62 into gripping engagement with the layer of blocks B immediately above the bottom layer during the raising of the grapple frame 26, whereby to lift the stack of blocks free of the layer deposited upon the cart.

In the over-all operation of the invention which is believed to be apparent from the foregoing description, a layer of suitably-oriented blocks B is rst formed on the cart 12, while the grapple frame 26 is lowered and the clamp members 62, 62 are in their disengaged position, the circuit to the grapple motor 52 tbeing de-energized, preferably manually, to retain the parts motionless at this time. It will be noted that the various hollow blocks B are disposed with the openings therethrough extending transversely to the direction of movement of the cart 12 along the rails 10 to facilitate the reception of the lift arms of a conventional fork-lift truck in the transverselydirected openings of the blocks. Upon the completion of a stack of blocks, including at least one layer a-bove the bottom layer, the circuit to the apparatus may be manually restored, whereupon the parts will be .so positioned that the toggle links 88 of the clamp mechanism will have engaged and closed the switch M5 so that the grapple frame 26 will automatically commence its upward movement and, in the course of same, will close the clamps 62, 62', causing them to grippingly engage the second layer of blocks or, in other words, the layer next to the bottom.

The blocks will be urged horizontally together 'by the clamping means with their vertical edges in firm abutting relation such as to form a rigid supporting structure capable of supporting thereon a number of additional layers of blocks Awithout the need for pallets or the like.

The stack of blocks will be fully elevated to the position of rest at which time actuation of the switch M4, by way of its associated cam, will arrest or de-energize the grapple elevating motor. The reduction gearing 16 will function as a braking means to support the loaded grapple in its fully-raised position of rest without need for further braking elements.

Once the stack is thus formed, it will normally be manually maintained and renewed, as required, by manual labor, it being necessary only to maintain the stack of sulcient height. Once the stack is built up to maintain an adequate supply for loading a number of carts, the workman may temporarily turn his attention to other duties and =add new blocks to the stack as the latter approaches depletion.

It will be noted that all blocks placed on the stack will be manually oriented with their openings disposed transversely, as shown. Thereafter, each time an empty cart moves to a position below the grapple frame, its motor will be de-energized by actuation of the switch M1, which switch will simultaneously energize the grapple motor 52 to initiate a complete cycle of automatic operation. Thus, in each such cycle, the grapple frame will lower the stack of blocks onto the cart, tripping the switch M2 by its associated cam to temporarily arrest the vertical movement of the grapple frame. At the same time, switch M2 through associated relays energizes solenoid valve 82 to initiate release of the clamping members 62, 62. Such release of the clamping members acts through their toggle linkage 88 to actuate the switch M5 for energizing the grapple motor to cause it to resume its operation. During the ensuing upward movement of the grapple frame 26, the clamps 62, 62 will remain disengaged for the first portion of such movement, or until they arrive at a level abreast of the layer of blocks immediately above the bottom layer. At this time, they will be engaged with the second layer through tropping of the second clamp switch M3 by its associated cam. The next layer above the bottom will thus be clamped and raised free of the bottom layer, leaving the latter deposited upon the cart 12 and supporting the entire stack of blocks on the new bottom layer. As the stack is raised by the grapple frame to the normal position of rest of the latter, the cam 112 on the crank shaft 32 actuates the switch M4 to simultaneously de-energize the driving motor 52 of the grapple, bringing it to rest with the stack in raised position above the deposited layer. The switch M4 simultaneously functions to close the circuit through the cart motor 14 whereby the cart 12 may move horizontally from beneath the supported stack to a further station at which a stack of iblocks or bricks of any particular type or orientation may be formed on the deposited bottom |layer, the blocks of which are oriented for reception of the fork-lift truck lift arms in their openings, whereby to serve as an effective substitute for the more conventionally-used pallet.

Having thus described -my invention, I claim:

1. Mechanism for dispensing successive horizontal layers of building blocks yfrom a stack of vertically superposed layers of said blocks comprising a rigid supporting structure, a grapple supported for vertical movement on said structure between a normally-raised position of rest and a relatively-lowered position, relatively horizontally-opposed and spaced clamp members carried by said grapple for reception between them of said stack of blocks and for movement horizontally into and from clamping engagement with said blocks, clamp actuating means normally maintaining said clamp members in clamping engagement with the lowermost layer of blocks in said stack whereby to support said stack in its entirety, means for sequentially lowering the said grapple from its said raised position to place said stack of blocks on a horizontal surface normally spaced ybelow said grapple and then raising said grapple to its said raised position, means automatically operative on each lowering of the lframe for disengaging said clamp members from the blocks whereby to leave said stack of blocks wholly supported on said surface, and means operative before completion of the raising of said frame to re-engage said clamp members with said stack of blocks at a level above the lowermost said layer vwhereby continued raising of the grapple frame will leave a layer of blocks deposited on said horizontal surface while litfing the remainder of said stack clear of the blocks thus deposited, to permit horizontal removal of the latter, said grapple including a generally rectangular horizontal frame, a pair of crank shafts rotatably supported on said supporting structure, ocnnecting rods respectively connecting said crank shafts to said frame, and means for rotating said crank shafts in unison to lower and raise said frame, said clamp members being carried by said frame.

2. Mechanism as defined in claim 1, including `means actuated by the positioning of said horizontal surface portion beneath said grapple for actuating said means for sequentially lowering and raising the grapple.

3. Mechanism as defined in claim 1, including means triggered by the positioning of said cart beneath the hopper for initiating a cycle of operation of said sequentially operating means.

4. Mechanism as defined in claim 1, in which said clamp members are provided with frictional clamping surfaces for abutting engagement with the opposed vertical surface portions only of a layer of blocks, said clamp members being free of horizontal projections beneath the blocks.

5. Mechanism as dened in claim 1, wherein said means automatically operative on each lowering of the frame for disengaging t-he clamp members, comprises an extensible and retractable pneumatic unit, and a :linkage operatively connecting said unit to the respective clamp members for engaging and disengaging movement of said respective members responsive to actuation of said unit, a reversing valve for controlling said unit, and means affixed to one of said crank shafts for controlling the said valve in accordance with the angular position of said crank shaft.

6. Mechanism as defined in claim 5, including an electric motor in driving relation with the respective crank shafts, a switch in circuit with said motor, said switch having a control arm disposed in the path of movement of said linkage, to control said motor in response to movement of said linkage.

References Cited UNITED STATES PATENTS 3,363,781 1/1968 Magnetti 214-85 X FOREIGN PATENTS 1,061,861 3/ 1967 Great Britain.

GERALD M. FORLENZA, Primary Examiner.

GEORGE F. ABRAHAM, Assistant Examiner.

U.S. Cl. X.R. 214-6 

